Thirteen Years War 1454–66

a war between the Teutonic Order and the Kingdom of Poland. It began in February 1454 as a revolt against the order by the Prussian League, which had been formed in 1440 when the low-ranking knights of Prussia, Eastern Pomerania, and various cities united in opposition to the order. Gdansk, Toruń, Elbląg;, and Königsberg were freed from the rule of the order, and in March 1454 the Polish king Casimir IV declared the incorporation of the territory of the Teutonic Order into Poland. The militia of the Polish gentry took possession of the territory but suffered defeat in September 1454 at Chojnice.

With the support of several German principalities, including Brandenburg, the order acquired the strength it needed to continue fighting for several years. The turning point of the Thirteen Years’ War was the victory of the Polish forces at Zarnowiec, near Puck, in 1462; the order also suffered a series of defeats in 1465 and 1466. The war was concluded by the Peace of Toruń (1466), which provided in part that the Kingdom of Poland would again have access to the Baltic Sea.